It will depend on the form of the verb. For example:
"Volver" means "to return" (as stated above) as in "vuelvo el próximo martes" (I will return next Tuesday), it is not restricted to people (as stated above), for example "el agua sube al cielo en forma de vapor y vuelve a la tierra en forma de gotas de lluvia" (water goes up to sky as vapor and returns to the soil as rain drops).
"Volverse" (pronominal form) means 1) "to become", for example "ella se volvió todo para mí" (she became everything to me); 2) "to turn", fo example "los alumnos se volvieron contra el profesor" (the students turned against the teacher).
"Devolver" means "to return", for example "quiero devolverte este libro" (I want to return this book to you).
"Devolverse" (pronominal form) also means "to return", "el bus se devuelve a la estación" (the bus returns to the station).
I hope this is helps.